Rock-drill.



H. J. H. NATHORST.

BOOK DRILL. I APPLIOATIQH FILED JAN. 23, 1907.

Patented July 19,1910.

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k v 1 c I. Inventor" KW ;.MM

2,0,1 mwsea mtniw Joann irALMAiz, na'rnzoits'r, orennnrvann 'MAIJMFALTfMALMBE RGET, f

. I I SWEDEN. I

I To all whom it may concern.

Be it known that I, HARRY JoHAN HJAL- MAR Na'rnons'r, a subject of the King of Sweden, and resident of Gellivare Malmfiilt, Malmberget, Sweden, have invented new andnseful Improvements in Rock-Drills, of which the following is a specification, refer.-

ence being had to the drawing accompanying and forming a part hereof.

This invention relates to improvements in rock-drills.

The object of the invention 'is to decrease, as much as possible, the detrimental vibrations of such machines.

The invention consists chiefly in tliat-thc hammer cylinder is mounted at right angles to the compressor cylinder 01 cylinders 'and parallel to the compressor shaft. so that the center lines of thehammer cylinder and the compressor shaft lie in one and the same plane.

In the drawing I have shown, by way of example, a central longitudinal section of a rock-drill embodying the invention.

Referring 'to the drawing, a is a rotary shaft journaled in bearings 11, b, and 0' and c are two cranks on the said shaft.

(1 and d are connecting rods, each connected'to one of the cranks c, and 0 At their other ends said connecting rods are connected to Distons e and a movable in the open cylinders f and respectively. Made integral with the cover of the cylinders and 1 extending parallel to the shaft ais the hammer cylinder 2'. is open, and in the said end a drillbit in having a shoulder at is inserted. At the other end the cylinder is provided with a bottom having an accurately centered hole. Through the passages l1. and It the cylinder communicates with the cylii'idcrs f and 7"" respectively.

is is the piston working in the cylinder "5, said piston being here constructed as a hammer and provided with a narrower cylin drical part Z fitting exactly in the said hole in the bottom of the cylinder 6.

o are-holes in the cylinders f and f said holes being so located that a communication with the open air is established, only when the pistons c and c are in the outermost. position of their strokes. I

The mode of operation of the machine is the same as in other similar machines. The

' Specification of Letters Patent.

At one end the cylinder atntea July 19,1910.

Application filed. January 23, 1907. Serial No. 353,731..

hammer is reciprocated "by compression alternately at one or the other side thereof so that the hammer is caused to strike the neck of the drill-bit. On account of the narrower part of the hammer entering the hole in the bottom of the cylinder at the end of the return stroke, an air cushion is formed preventing the hammer from striking the said bottom. Through the holes 0 losses by leakage a re compensated for at each. stroke. T

-By using a. loose hammer the advantage is gained that the machine always works with the same load and always synchronous with the con'ipressor, by which the machine as well as the motoris spared.

By placing the hannnercylinder at right angles to the compressor cylinder and-parallel to the crank shaft the advantage is gained that the vibrations caused by the recoil in the rock-drill and those caused by the motion of the cranks and pistons do not 00- operate'in their action upon the shaft and its bearings. By using two compressor cylinders mounted as shown in the drawing space is gained for the journaling necessary on account -of the great number of revolutions and the great strains.

It is obvious that the hammer cylinder may be placed elsewhere than at the cover of the compressor pistons, provided the hammer cylinder be mounted at right, aligles to the compressor cylii'iders and parallel to their crank shaft.

Having now described my invention what I claim as new and desire to secure. by Letters Patent is? 1. In a rock-drill, the combination of a. rotary crank-shaft. a compressor having cylinders extending at right anglesto the said crankshaft, '.oin n'essol' pistons driven by the said rrank-sliaft,a hamlncrcylindcrbuilt together with the compressor, said hammer cylinder being mounted at right anglesto I the compressor cylinders and parallel to the rotary crankshaft, and a hammer working in the hammer cylinder synchronously with the said compressor, substantially as and for the purpose set forth.

In a rock-drill, the' combination ofa rotary crank-shaft, a compressor having cylinders extending at rigl angles to the said crank-shaft, compress-or pistons driven by the said crank-shaf a hammer cylinder built together with the compressor and com former is'less than thatof the latter, submunicating constantly with the compressor stantially'as and for the pur ose set forth. cylinders, said hammer cylinder being I In'testnnony whereof -I ave signed my mounted at right. an les to the compressor name to this specification in'the presence of -5 cylinders and paralle to the rotary crank-- two subscribing witnesses.

shaft, and ahammer' working in the hemmer cylinder synchronously with the said HARRYJOHAN HJALMAR NATHOBST' compressor, the length of stroke of the said Witnesses: V

hammer being greater than that of the com- ELLEN Tnoi'r'm;

L0 pressor pistons, whereas the area of the AUGUST SiiRnNsEN; 

